Catering is possible is your city is totally dedicated to it.
I made some calculations on EN about an hour ago.
It might be possible if you can keep the used space extremely limited, make use of alternative goods production (like library set, mermaids paradise, trader I II and III from the MA ect.
Then you could have insane scores I think in 6 tournaments with the following rules.
It must be in the orc chapter (to unlock more than 222 provincies and at the same time don't be bothered with orcs mana ect in the tournament which saves space)
Get not more production than you need and keep space to an absolute minimum. do not build wasted space like MA or barracks, and maybe you might get away without a trader as well. (tho this might interfere with aquiring the correct buildings)
Do not give neighourly help and get rid of your bonus relics by leveling, then destroy rebuild ect of wonders.
Goals 0 relic bonus (you do not need it for alternative production buildings)
0 Wonderlevels
Absolute minimum of expansions, and those you do get have to be premium (go spire?)
This should get your costs in the tournament to near chapter 1 levels
When we look at a chapter 8 town, with only 21 expansions in total (6 base +15 premium we see these costs
Provincie 500
24.000 coins
2400 supplies
310 T1
230 T2
150 T3
These are very reasonable numbers that might actualy be possible to aquire in decent numbers.
And those coins / supply needs in a pinch are also very easy to aquire with a little bit of questing in numbers much greater then required so limited questing only.
Off course this is looking up the edges of possibilities but yes it surely is possible.
I also wonder with these numbers how much more expansions you can get away with before it no longer has a net gain.
I just grabbed a value I liked, but a much larger city might be possible as long as you keep that relic bonus at 0.
You would need to run some simulations to figure that out.
https://en.forum.elvenar.com/index.php?threads/upcoming-tournament-changes.12925/post-81612
just for lolz your mana plant / gum tree would provide 178 t3 per day/21 hours which is 77% of what you need to pay off province 50 using only a single square. which is very resonable. 1 expansion would provide 178*25=4450 t3 per day so 2-3 expansions would be enough to pay for 60-80 provinces
Endless scrolls 690 on 2 squares, you need little of that, then cross trade for t1 as you need very little compared to big players. they could take that tiny bit easily and you can see an insane tourney killer on negotiating alone with little effort, very little effort indeed.
https://en.forum.elvenar.com/index.php?threads/upcoming-tournament-changes.12925/post-81614
To build up an account like this takes a lot of time (tho time boosters from spire can help a huge amount in unlocking more provinces)
Especially to aquire all the set parts and premium expansions if you go the freebee route.
Tho additional worlds with 9 on US could make it pretty fast to get the diamonds.
But it would absolutly slay the competition in those 6 tournaments you play, and that with only logging in once or twice a day